The two voices of the opposed father figures, Fyodor Pavlovich and Zosima, are brilliantly distinct and compliment each other in a fascinating dialogue between the most debauched man in the district and the saint (one who is said to love sinners the most).
Fyodor's voice is layered with irony and performativity, whereas Zosima's voice is hieratic, laconic and directed at the depths of the heart itself. Their dialogue is fascinating because it's a duel hidden as confession. One is trying to provoke skin- deep responses and the other speaks to the soul itself. At the end Fyodor admits his own intention of making a scene and his hypocrisy, confirming, in a way, Zosima's assessment of not just his character but of lies themselves—both are having a dialogue with what remains "mysterious", one fills it with simulation, and the other is not afraid to reach into it and bring it to Earth. It seems unlikely that Fyodor will fall down to his feet and accept the supreme truth like the fictitious version of Diderot in the anecdote, even if he trembles thinking about it.
But Zosima is not "talking about Diderot" when he talks about lies. Fyodor doesn't speak the truth he feels within himself, instead, he anticipates responses to those around him. He can't bear to live seriously, so he both secretly rejoices daydreaming his victimhood and finds instant gratification in eliciting the responses he imagined in people, taking complete control of the situation and placing himself at the center of the stage. He's distanced from both himself and others because he lives in spectacle. He rebels against the gaze of the Other by drawing it into his own spectacle. His buffoonish nature is a parody of itself as well. Fyodor Pavlovich is surprisingly self- aware, but he sees no point in stopping the show. Nobody is safe from it, his provokations seek to bring others to his level. His character invites us to wonder how a person who is supposedly filled with shame could act so shamelessly and how beautiful lies are really that different from ugly ones.
@keepingupwiththekaramazovs
An interesting open access article I found about Postmodernism concerning Fyodor Pavlovich: I was surprised to find some analysis ideas I had thought of myself when studying those topics: https://www.jstor.org/stable/j.ctv2175qsg.15